Waste plastic from “throwaway” carrier bags can be readily converted into carbon nanotubes. The chemist who developed the technique has even used the nanotubes to make lithium-ion batteries.

This is called “upcycling” – converting a waste product into something more valuable. Finding ways to upcycle waste could encourage more recycling…

The process isn’t cheap, however. It involves an expensive catalyst in cobalt acetate, which is not easily recovered, to convert the high or low-density polyethylene (HDPE and LDPE) into carbon nanotubes. But if the nanotubes are then used to make lithium-ion or lithium-air batteries, that might overcome this problem, since these batteries are already recycled at the end of their use to recover cobalt.

Getting the bags to a recycling facility in the first place may be a hurdle as well. As the picture above shows, asking the public to put forth any effort sometimes seems to be asking too much.